Subsequent Events (Details) - USD ($) $ in Thousands	Dec. 31, 2018	Dec. 31, 2017
Subsequent Event [Line Items]
Derivative, Notional Amount	$ 607,747	$ 504,084
Maturity March 2023 [Domain] | Foreign Exchange Forward Contract [Member]
Subsequent Event [Line Items]
Derivative, Notional Amount	50,000
Maturity September 2024 [Domain] | Foreign Exchange Forward Contract [Member]
Subsequent Event [Line Items]
Derivative, Notional Amount	50,000
Maturity April 2025 [Domain] | Foreign Exchange Forward Contract [Member]
Subsequent Event [Line Items]
Derivative, Notional Amount	100,000
Maturity January 2028 [Domain] | Foreign Exchange Forward Contract [Member]
Subsequent Event [Line Items]
Derivative, Notional Amount	100,000
All Maturities [Domain] | Foreign Exchange Forward Contract [Member]
Subsequent Event [Line Items]
Derivative, Notional Amount	$ 300,000